Kafka's work provoked more than three decades of interpretations before Wagenbach provided information showing that Kafka was quite familiar with the work of Brentano and his Prague followers, including their unique conceptions of natural law, ethical concepts, and human acquaintance with them. Kafka took a lively interest in discussions in this Prague circle, and The Trial may without violence be read as a deliberate illustration for issues in philosophy of law as they would have been understood within this circle. This does not require that it be read as a reflection of Kafka's personality, nor does it require that he accepted Brentano's views.
Wagenbach demonstrated Kafka's familiarity with unique conceptions, in the work of Brentano and his Prague followers, of natural law and ethics. Issues involved in these conceptions are cogently illustrated in The Trial.
K. is tried for violating a law which is no positive law but a necessary condition for all positive law since all positive laws imply that they ought to be obeyed.
Brentano adamantly rejected all forms of nativism. The opposite of 'natural' in the phrase 'natural law' is not 'acquired' but 'conventional.' Acquaintance with natural norms is entirely acquired: persons having no such acquaintance can exist; K. is such a person. Natural norms, have a cognizable inherent correctness; any other norms oblige only through being authoritatively decreed. Conventional guilt or innocence is subject to influence. K.'s quest for a person to exert such influence on his behalf is evidence of his guilt. K. is unaware that absolute guilt is possible.
In the Prometheus myth related by Plato's Protagoras, a sense of justice and right is necessary for politically organized society. Without insight into the natural sanction for correct positive laws, citizens cannot fulfill the duty rationally to choose positive laws: citizens will wrong one another, cities perish, humankind will be threatened. The myth gives important clues to the imagery of the parable "Before the Law."
Every authentic act of willing requires that something be desired for its own sake. Since there is a plurality of intrinsic goods, authentic action requires recognizing the chosen action to be better than its alternatives. Acquaintance with good, evil, better, and worse is acquired, Brentano insisted, only by perceiving certain affects to be correct. Like judgments, affects are either blind or evident. Basic moral concepts arise like all others from perception.
K. could become innocent by acquiring the lacking concepts. Then, actual acquittal would be just despite his guilt when arrested. His trial tests whether he is likely to experience intrinsically correct emotions. Guilt would be objective, independent of any finding by the Court. K.'s guilt entails his lacking any such concept of absolute guilt. He is convinced that guilt depends entirely on the Court, is altogether a matter of authority. This is K.'s delusion concerning his relation to the Court and the Law, the delusion illustrated by the legend, "Before the Law."